Process for treating hydrocarbons



' Patented Feb. 21, 1939 UNITED STATES PATENT OFFICE PROCESS FOR TREATING HYDROCARBONS Charles Edwin Francis, Martinez, Calil.'., assignor to Shell Development Company, San Francisco, Calii'., a corporation of Delaware No Drawing. Application March 18, 1935, Serial No. 11,669

8 Claims.

tures which are either above or below the pour point.

Hydrocarbon oils which contain waxy constituents often losetheir limpidity because of the 10 rated wax appears either in the form of a. cloud within the oil or as a more or less crystalline precipitate which may remain dispersed throughout the oil. Frequently, the separatedwax will collect on the walls of the container, especially near the surface of the oil, or will rise to the oil surface. Such separation of wax often occurs at temperatures which are substantially above the congealing temperature of pour point of the oil, with the result that small constrictions in a lubricating system may become obstructed. The lack of clarity is in itself undesirable, because of the unattractive appearance of the oil. This separation of solid wax is mani- 5 fested both in the formation of clouds of dispersed more or less crystalline precipitates and in the formation of surface wax.

It is one object of my invention to provide a process for reducing, delaying or preventing the separation of such particles of wax by the addition of certaininnocuous substances to the oil, which are hereinafter referred to as wax suppressors". Other objects of my invention will be apparent from a reading of this specification.

I have found that the above stated objects can be realized by the addition to a wax bearing oil of small quantities of a natural non-parafiinic wax or of'mixtures of these waxes. The waxes which fall within the scope of the present invention are characterized by the large content of high molecular weight fatty acids and/or esters of said fatty acids with monoor poly-hydroxy alcohols, said acid or acid radical generally containing between ten and thi ty-five carbon atoms.

The natural w xes which may be used'in accordance with the present invention are white beeswax, yellow beeswax, spermaceti (cetaceium), wool wax, bayberry wax, candelilla wax, carnauba wax, Chinese wax, cocoa wax, 'cottonseparation of particles of solid wax. This sepawith mixtures of beeswax and carnauba wax and mixtures of beeswax and montan wax, and these constitute a preferred embodiment of my invention.

The waxes may be dissolved in the oil either singly or'in combination with one another. The effective quantity of wax suppressors required for inhibiting wax formation in diiferent oils varies V with the difierent wax suppressors and also depends upon the quantity and nature of the hydrocarbon wax in the oil and upon the temperature to which the oil is to be cooled. I have found that the effective quantities usually lie between 0.005% and 1.0% of the oil treated,.although under certain conditions as much as 1.5% may be desirable.

I have found that the above described waxes are also effective to reduce the pour point or congealing temperature of hydrocarbon oils. When used for this purpose somewhat larger quantities of natural wax are generally desirable, usually not exceeding 2%.

Such quantities of wax suppressors, as are used according to this invention to suppress the separation of wax, may have no significant efiect upon the pour point of the oil, but have a marked effect in preventing or retarding the separation of solid wax. When usedin larger concentration these natural waxes exhibit pour point reducing properties. Many .of the waxes may be increased in their effectiveness as wax suppressors and as pour point reducers by the saponification of their acid constituents. Thus, beeswax may be treated with lead carbonate or calcium oxide to convert the acidic constituents into lead and calcium soaps. The beeswax, thus treated, had a greater power for suppressing wax than the original beeswax.

The natural waxes may be added to the oils either at ordinary or at elevated temperatures. If the oil being treated'contains particles of separated solid paraflinic wax it is generally desirable to warm the oil to dissolve this paraflinic wax prior to its treatment. It was found, moreover, that the time required for dissolving the natural wax in the oil can be decreased greatly by warming and agitating the mixtures. For ex ample, it was found that solid beeswax dissolved very slowly in oil maintained at 'F., but when finely broken solid wax was added to oil properly agitated at E, 0.1% of beeswax was dissolved in two minutes.

' In large scale operations it is often desirable to dissolve a. large amount of wax in a small quanmy 01 oil andthen to add this concentrated oilnaturalwaxsolutiontothemainbodyofoil. Alternatively, the natural wax can be conveniently dissolved in the oil by placing fragments of thewax in a perforated container which is suspended inthe oil. In this manner, 0.1% of beeswax was dissolved in oil agitated at 175' I". in thirty minutes, when working with a 23!! barrel batch.

1b illustrate the use and elect ofmywax suppressors, the following examples are presented, it being understood that my invention is not limited to the particular waxes, temperatures, concentrations and details contained therein.

' trample I Emmple II A sample of the oil described in Example 1, containing 0.03% carnauba wax remained clear after four days storage at 45 F., the duration of the test.

Example III Samples of the oil described in Example I containing amounts of montan wax varying between 0.03% and 0.07% remained clear after flve months storage at 45 F., the duration of the test.

Example IV Samples of the oil described in Example I were treated with different blends of natural waxes and stored at 45 F. They each remained clear for the duration of the test as shown in the following table:

Duration oi Material added mstl days 0.017 beeswax +0.02% carnauba wax 137 0.02% beeswax +0.01%carnauba wax 137 0.l% beeswax+0.03% carnauba wax 146 0.05% beeswax +0.01% montan wax 130 0.057 boeswax +0.03% montax wax... 138 0.015%; Japan wax+0.0l5% carnauba wax. 13a 0.022% Japan wax +0.0(B% carnauba wax 130 Example V Blended western motor oils conforming to S. A. E. 30, 40, 50, 60 and 70 viscosity specifications each formed an appreciable haze when stored over night at 45 F. Different samples from each of these oils stored at 45 F.

remained clear for over three weeks, the duration of the tests, after the addition of my wax suppressors in the following amounts: 0.05% to 0.10% of beeswax, 0.01% to 0.05% of carnauba wax, 0.02% to 0.05% of a blend of three parts of beeswax and one part of carnauba wax.

Example VI Edeleanu raflinates from San Joaquin lubrieating oil stock conforming to S. A. E. 30, 40 and 50 viscosity specifications each formed .a haze when stored overnight at -0 F. Samples of each of these oils stored at 0 F. remained clear for over six weeks, the duration of the tests, after the addition of 0.05% to 0.10% of I auaaoz Example VII An'Edeleanu raihnate from San Joaquin lubrieating oil stock conforming to 8. A. E. 50 specification formed a haze when stored overnight at 70 F. The addition of 0.10% of beeswax prevented wax separation during a period of more than eleven weeks, the duration of the test.

As used in the present specification and claims, the expression suppression of wax" means the prevention, reduction or retardation of the formation of solid wax in oil.'

I claim as my invention:

1. A limpid normally liquid oil composition comprising a hydrocarbon oil containing paraflln wax in amount suflicient to impart an undesirably high cloud point to said oil in the absence of a wax suppressor and dissolved therein a quantity less than 2% of a natural non-paramnic wax from the group consisting of beeswax, spermaceti, bayberry wax, candelilla wax, carnauba wax. Chinese wax, cocoa wax, cotton seed wax, Japan wax and montan wax said quantity being .sufiicient to supress the separation of visible parainn wax above the pour point of the hydrocarbon oil.

2. A limpid normally liquid oil composition comprising a hydrocarbon oil containing paraihn wax in amount suflicient to impart an undesirably high cloud point to said oil in the absence of a wax suppressor and dissolved therein a quantity less than 2% of beeswax said quantity being sui'iicient to suppress separation of visible paraflln wax above the pour point of the hydrocarbon oil.

3. A limpid normally liquid oil composition comprising a hydrocarbon oil containing paramn wax in amount suflicient to impart an undesirably high cloud point to said 011 in the absence of a wax suppressor and dissolved therein a quantity less than 2% of a mixture of beeswax and a substance from the group consisting of montan wax and carnauba wax said quantity being sufficient to suppress separation of visible paramn wax above the pour point of the hydrocarbon oil.

4. A limpid normally liquid oil composition comprising a mineral oil containing parafiin wax in amount suflicient to impart an undesirably high cloud point to said 011 in the absence of a wax suppressor and between 0.005% and 1.5% of a substance from the group consisting of beeswax, spermaceti, bayberry wax, candelilla wax, carnauba wax, Chinese wax, cocoa wax, cotton seed wax, Japan wax, and montan wax for suppressing wax in hydrocarbon oil.

5. A limpid normally liquidoil composition comprising a mineral oil containing paraflln wax in amount sufllcient to impart an undesirably high cloud point to said oil in the absence of a wax suppressor and between 0.005% and 1.5% of beeswax.

6. A limpid normally liquid oil composition comprising a mineral oil containing paraflin wax in amount suflicient to impart an undesirably high cloud point to said oil in the absence of a wax suppressor and between 0.005% and, 1.5% of a mixture of beeswax and a substance from the group consisting of montan wax and camauba wax.

7. A limpid normally liquid oil composition, comprising a hydrocarbon oil containing paraflln wax in amounts sufllcient to impart an undesirably high cloud point to said oil in the absence of a wax suppressor, and dissolved therein a quantity less than 2% of a natural non-parafllnic wax. containing lead soaps resulting from con- 15 of a wax suppressor, and dissolved therein a quantity less than 2% of a natural n0nparaifinic wax containing calcium soaps resulting from converting its free fatty acid components to caloium soaps, said wax being selected from the group consisting of beeswax, spermaceti, bayberry wax, candelilla wax, carnauba wax, Chinese wax, cocoa wax, cotton seed wax, Japan wax, and montan wax, said quantity being sufficient to suppress the separation of visible paraflin wax 10 from the hydrocarbon oil.

CHARLES EDWIN FRANCIS. 

